Coronary artery disease (CAD), made clear.

The coronary arteries supply the heart muscle. Cholesterol-rich plaque can narrow these arteries and reduce blood flow, especially when the heart works harder.

CAD may cause chest pressure or breathlessness—or have no obvious symptoms.

A plaque can break open and trigger a blood clot. If the clot blocks the artery, part of the heart muscle loses its oxygen supply.

New or unexplained chest pressure that persists or returns needs emergency assessment.

Medicines and healthy habits lower future risk. Some people also need a stent or bypass surgery to improve blood flow. A stent holds an artery open; it does not cure the underlying disease.

Keep taking prescribed medicines and attending follow-up, even after a stent or bypass.